1. Field of the Invention
The present invention relates to a heat sink for an electronic device, and more particularly to a ceramic heat sink that has superior heat-dissipation properties and can be produced in high yield.
2. Description of the Related Art
A heat sink is a passive heat exchanger that transfers the heat generated by an electronic device to a fluid medium, often air or a liquid coolant, thereby allowing regulation of the device's temperature at optimal levels. The heat sink is usually made out of copper and/or aluminum and designed to maximize its surface area in contact with the cooling medium surrounding it. Copper is commonly used because it has many desirable properties for thermally efficient and durable heat exchangers. Aluminum is also used in applications where weight is a big concern.
As shown in FIG. 5, a conventional aluminum heat sink is shown, which generally includes a backing plate 51, a plurality of fins 52 formed on the backing plate 51. The backing plate 51 is of a square shape, with one side to be directly attached to an electronic device for absorbing the heat generated by the electronic device, and with the other side from which the fins 52 extend with a length for rapid transferring the heat absorbed by the base 51 to the cooling medium.
Apart from metallic materials, a heat sink may also be made of ceramics. A ceramic heat sink may perform well and has numerous advantages over conventional design and materials; however, it remains difficult to make and shape in a desired manner. That is, the shape of the ceramic heat sink is limited in technical and other aspects. Until now, a ceramic heat sink may be formed with tiny dotted bumps, as depicted in FIG. 6, or with wavy ribs having triangular cross sections, as depicted in FIG. 7. These two ceramic heat sinks share one thing in common. That is, both the bumps and the ribs are short in height. It can therefore hardly maximize their surface areas for further improvement of the heat dissipation properties.
One of a desired-shaped ceramic heat sink is illustrated in U.S. Patent Pub. No. 2012/0255719 (2012), reproduced in FIG. 8. In this heat sink, the fins are of great height in comparison to the backing plate, and the heat sink seems to be a perfect craft for high-efficiency heat dissipation. However, in reality, the heat sink product can hardly be made or found in the market. The materials of the product tend to stick to the mold while demolding, causing the final product be damaged and disqualified.